The thymus gland is an organ in your chest, underneath the breastbone. As part of the lymphatic system, in your body’s immune system, the thymus gland produces white blood cells called lymphocytes, which help your body fight infection.
There are two main kinds of thymus cancer: thymoma and thymic carcinoma, and both are rare. Cancer occurs when cancer cells form on the outside surface of the thymus. Thymic carcinoma is more aggressive and more difficult to treat than thymoma. People with thymoma cancer typically have an autoimmune disease as well, such as myasthenia gravis, acquired pure red cell aplasia, and rheumatoid arthritis. Thymic carcinoma is also referred to as type C thymoma.
According to the American Cancer Society, roughly 4 out of 10 people have no symptoms when they’re diagnosed with thymus cancer. Many times, cancer is found during other medical tests or exams. When symptoms do occur, they may include a persistent cough, breathing difficulties, or chest pain. Because of how nonspecific the symptoms are, diagnosis can be delayed.
A general physical exam will be done to see if you have any unusual findings, such as lumps. Other tests are used to diagnose thymus cancer:
- chest X-ray
- imaging tests such as PET scan, CT scan, and MRI
- biopsy with microscopic examination of thymus cells
A staging system is a method of classifying cancer based on its size, extent, and other characteristics. There is no single agreed upon staging system for thymomas, however many doctors use the Masaoka staging system, which organizes the disease into stage 1 through stage 4. Stage 1 is noninvasive, whereas in stage 4, the cancer has spread to distant organs such as the liver or kidneys.
Treatment for these cancers depends on the extent of disease, indicated by its stage, as well as your overall health. Although thymic carcinoma is typically widespread at the time of diagnosis, this staging system may still be used.
There are several treatments available for thymus cancer, depending on the stage of the disease. A treatment plan may include more than one kind of treatment.
Surgery is the surest way to eliminate the cancer and is performed whenever possible to remove the tumor, thymus gland, or other diseased tissues. If the cancer is too large or has spread too far to be completely removed, your doctor may recommend radiation to first shrink the tumor and then operate. They may also decide to remove as much of the cancer as possible and then proceed with another treatment option.
Radiation or chemotherapy may be given before or after surgery. Radiation uses high-energy X-rays to kill cancer cells by damaging their DNA. Chemotherapy involves the use of drugs to kill cancer cells. Chemotherapy drugs are usually given intravenously (through a vein), enabling the medication to work throughout the entire body, and killing cancer that may have spread to other areas.
Hormone therapy is another treatment option for thymus cancers. Some hormones cause the cancer to grow, and if your cancer is found to have hormone receptors (places for hormones to attach), drugs may be given to block the action of hormones on the cancer cells.
Because thymus cancer is so rare, you may want to ask your doctor about taking part in a clinical trial. These are trials in which new treatments for the cancer are done to help determine their effectiveness. Participants are closely monitored and can discontinue participation at any time. Clinical trials are not right for everyone, but your doctor can tell you whether this is an option for you.
Long-term outlook for thymus cancers depends on a multitude of factors, including your age and overall health, whether surgery removed all of the tumor, the type of cancer cells present, and the stage of the disease. Once treatment is over, follow-up visits are necessary to monitor any side effects from the treatment and to ensure that the cancer has not returned.
The risk of the cancer returning is very real and can be a source of anxiety for people. Ask your doctor about support groups or counseling if you find yourself struggling emotionally or feel you might want to talk to someone.